Since 2012 there have been 4 dogs in Southern Ontario diagnosed with Echinococcus multilocularis. This is a very small tapeworm which has the potential to cause disease not only in pets but also in people. This parasite has never before been found in Ontario but is suspected to be carried in the wild dog population (coyotes and foxes). The parasites natural lifecycle starts in the gut of coyotes or foxes (definitive hosts), they then shed eggs in their feces that are ingested by small rodents like voles and mice (intermediate hosts). In this animal the parasite travels to the liver and causes a tumour-like growth in the liver. When the rodent is ingested by the fox or coyote the parasite makes it’s way back to the gut and starts producing eggs again. The dogs that have been diagnosed in Ontario had infections consistent with being an intermediate host (so likely got infected from ingesting feces of coyotes or foxes). They also have the potential of being definitive hosts if they ingest a rodent that has been infected. In these cases they have the ability to spread parasite eggs just like a coyote or fox. Obviously, this is concerning for our pets but also for us. The incubation period (time between when we get infected and when we become ill) is 5-15 years in people. This means that it is possible we could see humans with this disease in the future even though none have been diagnosed yet. All people in contact with the diagnosed dogs in Ontario have been tested and luckily were found not to be infected.
If your dog spends lots of time off leash in wooded areas or eats rodents you may want to consider having a fecal sample tested and or having them dewormed for tapeworms on a regular basis. Tapeworm segments are visible to the naked eye and appear like grains of rice on feces or around the rectum. There is no way to tell this tapeworm apart from the more common and less concerning dipylidium caninum on fecal examination but the same medication is used to treat both.
if you have any questions or concerns please don’t hesitate to call or book an appointment to speak to one our vets (905)385-5354